Gear tooth chamfering machine



Sept. 22, 1942. I R. E. CROSS GEAR TOOTH CHAMFERING MACHINE Filed Jan. 27, 1959 ll Sheets-Sheet l I.. OO O Q| it I'll .22. m Z Z 2 o NAM/.1 f. W; .2 22 O O O. O O J W 5. Q Q. u MW 2 Y L15 9 m MI 5, f 2 1 I 4. HI A I MW" INVENTOR F4! .2. (Pa is.

ATTORNEY I Sept. 22, 1942. R. E. CROSS 2,295,270

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GEAR TOOTH GHAMFERING MACHINE Filed Jan. 27, 1939 ll Sheets-Sheet 3 ZN VENTOR A TTORNEY Sept. 22, 1942. Rcss 2 ,296,270

GEAR TOOTH CHAMFERING MACHINE Filed Jan. 27, 19:59 11 Sheets-Sheet 4 [N VENTOR A TTORNE V Sept. 22, 1942. R. a. (mess 2 GEAR TOOTH CHAMFERING MACHINE Filed Jan. 27, 1939 11 Sheets-Sheet 5 [N VEN TOR A TTORNE Y p 94 R. E. CROSS 2,296,270

' GEAR TOOTH CHAMFERING MACHINE Filed Jan. 27, 1939 Y 11 Shets-Sheet 6 $9 40 .9 E zdzpz 2. 62232 BY Z ZM A TTORNE Y Sept. 22, 1942. R. E. paoss 2,296,270

GEAR TOOTH QHAMFERING MACHINE Filed Jan. 27, 1939 11 Sheets-Sheet '1 Z6 7 A TTORNE Y P 1942- R. cRoss 2,296,270

' GEAR TOOTH CHAMFERING MACHINE FiledJan. 27, 1939 i1 Sheeis-Sheet a [N VENTOR @1435. BY i A TTORNE Y Sept. 22, 1942. R. E. CROSS 2,296,270

GEAR TOOTH CHAMFERING MACHINE INVENTO\R A TTORNE Y Sept. 22, 1942. R; E. @851 2,296,210;

GEAR TOOTH CHAMFERING MACHINE File d Jan. 27; 1939 11 She ets-Sheet 1o INVIYENTOR Z. 'r'ass i/am ATTORNEY Sept. 22, 1942. R. E. @655 GEAR TOOTH CHAMFERING MACHINE l1 Sheets-Sheet ll INVENTOR Filed Jan. 27, 1959 BY g zwfm A TTORNEY Patented Sept. 22, 1942 UNITED STATES PATENT OFFICE GEAR TOOTH CHAMFERING MACHINE Ralph E. Cross, Detroit, Mich.

Application January 27, 1939, Serial No. 253,157

7 Claims.

This invention relates to gear tooth chamfering machines and the object of the invention is to provide a machine for chamfering the ends of gear teeth by use of a rotary cutter which bevels the end edges of the gear teeth as the gear is rotated.

One of the particular objects of the invention is to provide a two point hollow mill cutter arranged to chamfer one side of one gear tooth and the opposite side of the next gear tooth with each point. 1

Another object of the invention is to provide a two point hollow mill cutter arranged so that each point of the cutter will chamfer one face of twoadjacent gear teeth.

Another object of the invention is to provide a gear tooth chamfering machine having a two point cutter which is rotated at relatively high speed and the gear being turned in the same direction as the cutter at a relatively. lower speed and so arranged that each cutter point cuts a chamfer on two adjacent gear teeth.

A further object of the invention is to provide a two point gear tooth cutter which will chamfer the ends of the gear teeth by a continuous rota tion of the gear and cutter whereby the points of the cutter travel continuously through the same orbit on thegear teeth allowing the cutter to be fed into the teeth to increase the depth of the cut as the cutter and gear are rotated.

Another object of the invention is to chamfer both sides of the gear teeth by a double pointed cutter in which one point completes one cutting operation on a tooth and the second cutter performs the other cutting operation on the tooth thus chamfering both sides of the tooth as the gear and cutter are rotated.

A further object of the invention is to provide a machine having a rotating Spindle on Which the gear is mounted and having a rotating cutter head for moving the cutter into the gear to chamfer the gear teeth by rotary cutter motion and by relatively rotating the gear and the cutter.

Another object of the invention is to provide a gear tooth chamfering machine having a motor driven cutter provided with two cutting points and a work spindle driven from the cutter head and in relation thereto and supporting a gear having teeth to be chamfered, thegear and cutter being rotated to chamfer the edges of the gear teeth by continuous rotary motion, the cutter points beingarranged to travel through orbits over the ends of the gear teeth and being arranged to chamfer the opposite edges of the gear teeth as the gear and cutter are rotated.

Another object of the invention is to provide a work holding spindle which may be adjusted in angular position in relation tothe cutter and the cutter being arranged to be fed into the gear teeth as the cutter and gear are rotated.

These objects and the several novel features of the invention are hereinafter more fully described and claimed and the preferred form of construction by which these objects are attained is shown in the accompanying drawings in which Fig. 1 is a front elevation of a gear tooth chamferingr machine embodying my invention and broken away to show the construction.

Fig. 2 is a side elevation of the machine taken from the right hand side of Fig. 1.

Fig. 3 is an elevation of the machine taken from the left hand side of Fig. 1.

Fig. 4 is a top plan view of the machine.

Fig. 5 is an enlarged section taken on line 5-5 of Fig. 1.

Fig. 6 is an enlarged section taken on line 6--6 of Fig. 4.

Fig. 7 is an enlarged section taken on line T-1 of Fig. 5.

Fig. 8 is an enlarged section taken on line 88 of Fig. 2.

Fig. 9 is an enlarged section taken on line 9-9 of Fig. 1.

Fig. 10 is an enlarged section taken on line l0l0 of Fig. 2.

Fig. 11 is a section taken on line I l|l of Fig. 8.

Fig. 12 is a side elevation of a gear showing the teeth after chamfering by the machine.

Fig. 13 is a plan view of the gear shown in Fig. 12. 1

Fig. 14 is a view showing the gauge for setting the hollow mill cutter.

Fig. 15 is an end view of the cutter and gauge.

Fig. 16 is a rear view of the machine base broken away to show the hydraulic pump and connections.

Fig. 1'7 is a section taken on line l'I-Il of Fig. 16.

Fig. 18 is a detail section through the cutter and a tooth being chamfered.

Fig. 19 is a diagrammatic view showing the orbits of the cutter points in relation to the gear teeth being chamfered.

The machine comprises a base I having a chip compartment 2 extending forward therefrom and provided with an upright portion 3 from which the cutter head 4 extends as shown in Figs. 1, 2, 3 and l. The cutter head 4 is shown in section in Fig. 6 and contains an electric motor 5 providing a direct drive for the cutter 6. This cutter as shown in Figs. 1, 2, 3, 14, 15 and 18 is provided with two cutting points and 8 traveling in a circular orbit. As shown in Fig. 6, the electric motor shaft is provided with a beveled gear 9 thereon meshing with the beveled gear I on the shaft II and the gear |2 on the opposite end of this shaft meshes with the gear |3 on the shaft I4. This shaft I4, as shown in Figs. 1 and 2, is enclosed within a telescoping housing I5 and is provided with a splined lower end I6 extending through the gear H which meshes with a gear I8. This gear 3 is shown more particularly in Fig. 10 and is secured to the end of a splined shaft |9 which extends into the base The splined shaft l9 extends through a spline sleeve to which the beveled gear 2| is secured and this beveled gear 2| meshes with the beveled gear 22 which is rotatably mounted in the bearing member 23 shown in Figs. 10 and 11. A spur gear 25 is secured to rotate with the beveled gear 22 and meshes with the gear 26 shown in Figs. 10 and 11. The gear 26 is mounted on a shaft 2'! which is shown in Figs. 8 and 11 and secured to the opposite end of this shaft 21 is a gear 28 shown at the right of Fig. 9 and also shown in Figs. 1 and 11. This shaft 21 as will be understood from Figs. 1 and 11 carries the drive through the work head 29 and about the work spindle 36.

Meshing with the gear 28 is a gear 30 shown in Figs. 1, 9 and 11 and this gear 30 meshes with a gear 3| and these gears are mounted in the housing 32 which is secured to the work head 29. The gear 3| is secured to a shaft 33 and this shaft 33 as shown more particularly in Figs. 8 and 9 is provided with a worm 34 thereon which meshes with a worm gear 35 shown in Fig. 8. This worm gear is secured to the rotatable work spindle 36 so that this work spindle is rotated through the several shafts and gearing from the cutter shaft carried in the cutter head. The work spindle 36 is rotatably mounted in the work head 29 shown more particularly in Figs. 1, 8, 9 and 11. Formed integrally with the housing 29 is a flange 31 carrying the bolt 38 and diametrically opposite the housing is provided with a lug 39 carrying a bolt 4|]. These bolts are mounted in arcuate slots 4| and 42 provided in a plate 43. This plate 43 as shown in Fig. 9 is formed with ways 44 and 45 which ride on the flanges 46 of the base as will be understood from Figs. 1, 2 and 9. By this arrangement, the plate with the entire work head thereon may be moved laterally of the base on the flanges 46. To accomplish this lateral movement, a screw shaft 41 is provided having a squared end 48 extending from the base as will be understood from Figs. 2 and 10. This shaft 4'! is threaded through a lug 49 on the member 24 which carries the bearing 23 and is shown in Figs. 9, 10 and 11. Thus, by turning the shaft 41 by applying a crank to the squared end 48, the member 24 and entire work head may be moved horizontally on the ways 46 shown in Fig. 1.

The splined shaft I9 extending through the splined sleeve 20 will allow such movement and still maintain the gears properly connected. By loosening the bolts 38 and 4|] shown in Fig. 8 the work head may be turned in the slots 4| and 42 to give any desired angular position of the work head. In order to allow such turning movement of the work head about its axis, the axis of the gear 25 is arranged as the central axis of the work head and thus when the work head is turned about this axis the gear 26 will roll about the gear 25 to the set position without unmeshing these gears, as will be understood from Figs. 10 and 11. Thus, by this arrangement, the work head may be moved horizontally in either direction and may be turned to any angular position and will still maintain the driving connection for rotating the Work head. In order to accurately adjust the head in angular position, the flange 31 is provided with a point 56 riding over a scale 5| shown more particularly in Figs. 8, 9, 11 and 17.

When so assembled as shown in Fig. 8, the gear is held in fixed position by the shaft 55 controlled by the hydraulic cylinder 550. shown in Figs. 2 and 8 and is then ready for the chamfering operation. The cutter for chamfering the ends of the teeth is a hollow mill cutter having two diametrically opposite cutting points and 8.

The cutter does not necessarily have two points but could have three or four or any number. Of course, this would change the timing relation between the rotation of the cutter and the rotation of the gear being chamfered.

In order to chamfer the teeth ends, it is necessary to feed this cutter into the teeth. This is accomplished by moving the cutter head downwardly which may be attained by mechanical means or by hydraulic means, such as used in standard practice, for this type of operation. In order to allow upward and downward movement of the cutter head, the shaft I4 is provided with the splined end l6 as hereinbefore described to slide through the spline gear I! and the telescoping housing I5 is provided for the shaft 4 to maintain the shaft enclosed and free from dirt. As shown in Figs. 3, 4 and 5, a member 6| is slidable on the upright portion 3 of the base and. this member may be raised or lowered by means of a hydraulic cylinder 62 shown in Figs. 5 and 7. This cylinder 62 is a standard hydraulic feed cylinder for raising or lowering the cutter head. However, it is also desired to adjust the position of the cutter head on this slide 6| and this is accomplished by means of the hand wheel shown in Figs. 3, 4 and 5 which is connected to raise or lower the cutter head 4 on the slide 6| so as to adjust the position of the cutter head on the slide and thus adjust the position of the cutter in relation to the work or gear to be operated upon. An adjustable screw stop 63 is provided as shown in Figs. 1 and 3 to limit the downward movement of the cutter head and a push button switch 9| is provided on the base for manually starting and stopping the motor in the cutter head.

As shown in Fig. 8, the hollow mill cutter is advanced into the gear teeth at an angle due to the angular setting of the work head and this cutter is rotating in a counter-clockwise direction as suggested by the dotted line and arrow in Fig. 13 while the gear 58 is rotating in a clockwise direction but the cutter points are traveling over the gear teeth at a faster speed than the gear teeth are rotating. It is necessary to set the cutter teeth so that the cutter teeth will travel in proper position over the gear teeth and it is for this reason that the work spindle is driven by shaftin and gearing from the cutter shaft. As hereinbefore described, the hollow mill cutter is provided with two teeth or cutting points 1 and 8 and these teeth travel through the dotted circle 66 shown in Fig. 13. The cutter is also shown in section in Fig. 18 which illustrates the method in which the teeth of the cutter travel over the ends of the teeth of the gear. The first tooth of the cutter will travel over the face 14 of one gear tooth and. over the face 15 of the next gear tooth. As this gear is rotating in a clockwise direction at a constant speed, the next tooth of the cutter will travel over the face 16 of the next tooth and the face 11 of the succeeding tooth. Thus, each cutter cuts two opposite tooth faces at the same time and the second cutter point also cuts two opposite faces of two teeth so that in one complete rotation. of the cutter the chamfering of the faces 14 and H on one tooth is completed while one face of the preceding and succeeding tooth is chamfered to provide the chamfered faces 16 and I5.

. However, as the gear is continued in its rotation, both teeth edges of all the teeth are chamfered by the completion of one revolution of the gear. However, the cutter is not fed to the full depth upon the first revolution of the gear but can continue to be fed into the gear teeth on the succeedin revolutions of the gear until the chamfering of the teeth is completed to the desired depth to provide a finished gear as shown in Figs. 12 and 13. As both the cutter and gear are rotating it will thus be seen that the ends of the gear teeth may be chamf'ered very rapidly without indexing the gear or cutter as long as the gear and cutter are set in proper relation at the beginning of the cutting operation. For a diiferent sized gear, it will be necessary to provide different diameter cutters and a different gear 3|. Each cutter is designed for. the particular gear on which it operates, or more specifically for the pitch of the gear on which it opershown in dotted lines To and full lines 80 The a.

dotted line la. represents the orbit of the cutter point I while the full line represents the orbit of the cutter point 8 and the diagram is drawn as though the gear teeth were stationary and the axis of the cutter were moving as this is the best way to show the orbit of the cutter teeth in relation to the gear teeth. Consequently, the axis of rotation of the cutter is shown as progressing to the right of Fig. 19 by the different points 86 on the centerline 1|.

What actually happens is that the gear teeth are moving to the left of Fig. 19 while the axis of the cutter remains stationary but the cutter points are traveling in the same direction as the gear teeth at a relatively more rapid speed than the gear teeth. There are four gear teeth shown in Figs. 13 and 19, A, B, C and D. The orbit of the cutter point I is indicated by the dotted line To while the orbit of the cutter point 8 is indicated by the full line 8a. The line on which the cutter tool axis travels is represented by the straight line H. The cutting points of the tool when traveling over the gear teeth are traveling in the same direction as the gear teeth but at a greater rate of speed though the actual rotation on the tooth B. The cutter point I travels on the line la to the point 18 whilethe cutter point 8 travels on the line 8a to the point 19. At these points 18 and 19, the cutter points have each completed a full revolution and the cutter itself has traveled a. complete revolution. However, continued movement of the cutter point I on the line la. will cut the face 80 on the tooth D and the face 8| on the gear tooth C and so on around the gear.

It will thus be seen that one complete revolution of the cutter will complete the chamfering of the tooth B by cutting the faces 74 and TI thereon and in addition, will complete one face l5 on the tooth A and one face 16 on the tooth C. However, the cutting tool does not start at its full depth but is fed'into the gear gradually to keepv taking deeper cuts on the teeth until the chamfering of all teeth is completed by several rotations of the gear which depend upon the speed at which the cutter is advanced into the work.

It will be noted that the cutting faces of the cutter must be maintained in an accurate timed relation with the spacing of the gear teeth at all times. If this relationship is not held the orbits of the cutter points will not be tangential to the center lines between the teeth and thus a greater bevelwould. be cut off from. one gear tooth than another. Therefore, when the faces of the cutter teeth 1 and 8 are resharpened it is necessary to remove the cutter and replace it in the cutter spindle after sharpening so thatthe cutting faces are in the. same relationship to the gear tooth spaces as prior to the time the cutter was removed. To do this, the gauge 64 shown in Figs. 14 and 15 is utilized. Before removing the cutter the gauge is set so that one of the two cutter points 1 or 8 rest on the face 8! of the gauge. The cutter is then removed by loosening the screw 65 and sharpened. After sharpening, the cutter is replaced in the spindle and rotated against the gauge and the screw 65 is tightened securing the cutter firmly in place. The gauge is then removed and the cutting edge of the cutter is now in the same relative position to the spindle and therefore to the gear tooth spaces as before it was sharpened.

It is also necessary when putting a new gear on the work spindle to place it so the gear teeth are in the proper relative relation to the cutter points and their orbit. Several means are common in other methods of chamfering for accomplishing this but the means I prefer for this method of chamfering is a finger 52 which enters in the tooth space of the gear and locates it radially on its axis. This finger may remain between the teeth of the gear while it is being ch-amfered and act as a driver or it may be removed from between the gear teeth and the gear driven by friction. In any case, the finger must be fastened to the work spindle or be a part thereof and rotate with the work spindle so as to maintain the proper relative, rotative relation with the cutter points and their orbit.

In order to provide hydraulic pressure for opcrating the head 4 and other parts of the machine which it may be desired to operate by hydraulic pressure, the electric motor and pump for providing such hydraulic pressure is housed in thebase I as shown in Figs. 16 and 1'7. This may be standard equipment as provided for this purpose and such equipment together with the connections is housed in the base I. The hydraulic equipment forms no particular part of this invention and consequently is not described in detail. The cutter head is carried by the upright portion 3 of the machine shown in Figs. 1 and 3 and this may be moved horizontally on the ways ll provided on the base I as shown in Figs. 1 and 16. In order to allow such movement, the drive shaft l4 may turn on the axis of the gear 18 as will be understood from Fig. 2 so that movement of the upper machine portion 3 and cutter head 4 in either direction may be accomplished without disturbing the mechanical drive.

From the foregoing description it becomes evident that the device is very eificient in operation, will drive the work from the cutter head at a relative speed in relation to the cutter head, will chamfer the end edges of the gear teeth by a continuous rotary motion of the cutter and gear, will chamfer the teeth of the gear in the shortest possible time and provides a device which accomplishes the objects described.

Having thus fully described my invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is:

1. In a machine for chamfering the ends of gear teeth, a base, a cutter head, means for moving the cutter head vertically on the base, means providing for adjustment of the cutter head horizontally on the base, a work head having a work holding spindle rotatably mounted therein, means for adjusting the work head horizontally, means for adjusting the Work head about an axis at a right angle to the axis of rotation of the spindle to vary the angle of the spindle, a cutter mounted in the cutter head, the gear to be chamfered being mounted on the work holding spindle, drive means connecting the cutter and work holding spindle whereby the cutter and gear are rotated continuously in opposite directions, the cutter having two diametrically opposed cutting teeth each arranged to chamfer opposite side edges of successive teeth as the cutter is moved into engagement with the gear,

2. In a, machine for chamfering the ends of gear teeth, the combination with two cutters arranged on opposite sides of a common center of rotation and each adapted to engage the opposite side edges of successive gear teeth, of common means for moving the cutters through a continuous orbit about a fixed axis and for continuously moving the gear about a fixed axis to move the teeth thereof in succession into the orbit of the cutters wherein one cutter chamfers a side edge of a tooth and the other cutter chamfers the opposite side edge thereof in succession.

3. In a machine for chamfering the ends of gear teeth, the combination with a cutter having a pair of diametrically opposed cutting points continuously rotatable through an orbit about a common axis, means for moving the cutter points through the orbit and means for continuously revolving the gear during rotation of the cutter about a fixed axis to bring the teeth thereof in succession into the orbit of the cutters in such relation that one cutter chamfers one side of a tooth and the other cutter chamfers the opposite side edge of the same tooth.

4. In a machine for chamfering the ends of gear teeth, a base having an upright portion, a vertically movable slide mounted on the upright portion, a cutter head adjustably mounted on the slide, means for raising and lowering the slide, adjustable stop means limiting downward movement of the slide, a work head adjustable horizontally on the base beneath the cutter head, means for adjusting the work head angularly in relation to the cuter head, a cutter mounted in the cutter head, a work holding spindle rotatably mounted in the work head, drive means connecting the cutter and spindle for driving the same at relative speeds, means for mounting a gear on the spindle, means for fixing the position of the gear in relation to the position of the cutter teeth and the drive means being arranged to drive the cutter and gear continuously so that as the cutter is moved into the gear it will round the ends of the gear teeth.

5. In a machine for chamfering the ends of gear teeth, a base, an upright portion adjustable horizontally on the base, a vertically movable slide mounted on the upright portion, a cutter head adjustable vertically on the slide, means for raising and lowering the slide, adjustable stop means limiting downward movement of the cutter head, an electric motor in the cutter head, a cutter driven by the electric motor, a work head adjustable horizontally on the base beneath the cutter head, means for adjusting the work head in a vertical plane about a central axis, a

. work holding spindle rotatably mounted in the work head, drive means connecting the electric motor and work spindle for driving the same continuously at relative speeds, means for mounting a gear on the spindle, means for fixing the relative position of the gear teeth in relation to the position of the cutter teeth and hydraulically operated means for holding the gear in fixed position on the work spindle.

6. In a machine for chamfering the ends of gear teeth, a base, an upright portion adjustable horizontally on the base, a vertically movable slide mounted on the upright portion, a cutter head adjustable vertically on the slide, means for raising and lowering the slide, adjustable stop means limiting downward movement of the cutter head, a work head adjustable horizontally on the base beneath the cutter head, means for I adjusting the work head in a vertical plane about a central axis, a cutter mounted in the cutter head, a work holding spindle rotatably mounted in the work head, drive means connecting the cutter and spindle for driving the same continuously at relative speeds, means for mounting a gear on the spindle, and means for fixing the relative position of the gear teeth in relation to the position of the cutter teeth.

'7. In a machine for chamfering the ends of gear teeth, a cutter, means for continuously rotating the cutter through an orbit about an axis, a rotatable holder for a gear to be operated upon, a gear train for continuously revolving the gear and holder about a fixed axis to bring the teeth thereof in succession to within the orbit of the cutter in timed relation with the cutter movement, said gear train including provision for change of gears for varying the speed of rotation of the gear to be operated on whereby gears of different diameters and numbers of teeth are caused to move successively to cutting position in timed relation with the speed of rotation of the cutter, and means for turning the holder about an axis at an angle to its axis of rotation to permit use with gears requiring different angles of chamfer.

RALPH E. CROSS. 

